U.S. patent application number 12/472700 was filed with the patent office on 2010-12-02 for print bar.
Invention is credited to Dustin W. Blair, Winthrop Childers.
Application Number | 20100302311 12/472700 |
Document ID | / |
Family ID | 43219747 |
Filed Date | 2010-12-02 |
United States Patent
Application |
20100302311 |
Kind Code |
A1 |
Blair; Dustin W. ; et
al. |
December 2, 2010 |
Print Bar
Abstract
In one embodiment, a print bar includes a substrate having a
longer part and a shorter part extending along and parallel to the
longer part such that each end of the longer part extends past each
end of the shorter part; and multiple printhead dies on the longer
part of the substrate. In another embodiment, a modular print bar
includes a first module including multiple printhead dies joined
together end to end; and a second module including multiple
printhead dies joined together end to end The second module is
lapped together end to end with the first module.
Inventors: |
Blair; Dustin W.;
(Escondido, CA) ; Childers; Winthrop; (San Diego,
CA) |
Correspondence
Address: |
HEWLETT-PACKARD COMPANY;Intellectual Property Administration
3404 E. Harmony Road, Mail Stop 35
FORT COLLINS
CO
80528
US
|
Family ID: |
43219747 |
Appl. No.: |
12/472700 |
Filed: |
May 27, 2009 |
Current U.S.
Class: |
347/42 |
Current CPC
Class: |
B41J 2202/20 20130101;
B41J 2/155 20130101 |
Class at
Publication: |
347/42 |
International
Class: |
B41J 2/155 20060101
B41J002/155 |
Claims
1. A print bar, comprising: a substrate having a longer part and a
shorter part extending along and parallel to the longer part such
that each end of the longer part extends past each end of the
shorter part; and multiple printhead dies on the longer part of the
substrate.
2. The print bar of claim 1, wherein the multiple printhead dies
are arranged on the substrate such that an array of orifices on
each printhead die extends parallel to a long axis of the
substrate.
3. The print bar of claim 2, wherein: the substrate comprises
multiple substrates each having a longer part of the substrate and
a shorter part extending along and parallel to the longer part such
that each end of the longer part extends past each end of the
shorter part, the substrates arranged end to end in a linear
configuration in which one end of the longer part of one substrate
adjoins one end of the shorter part of an adjoining substrate; each
substrate has multiple printhead dies arranged on the substrate
such that an array of orifices on each printhead die extends
parallel to the long axis of the substrate; shorter edges along the
shorter parts of the substrates are substantially aligned with and
parallel to one another; and longer edges along the longer parts of
the substrates are substantially aligned with and parallel to one
another.
4. A modular print bar, comprising: a first module including
multiple printhead dies joined together end to end; and a second
module including multiple printhead dies joined together end to
end, the second module lapped together end to end with the first
module.
5. The print bar of claim 4, wherein an orifice array in a first
printhead die in the second module is offset from an orifice array
in a last printhead die in the first module in a media transport
direction but otherwise forms a substantially seamless continuation
of the orifice array in a transverse direction.
6. The print bar of claim 4, wherein an orifice array in a first
printhead die in the second module is offset from an orifice array
in a last printhead die in the first module in a media transport
direction and overlaps the orifice array in the last printhead die
in the first module in a transverse direction.
7. The print bar of claim 4, wherein: each of the first and second
modules is characterized by a longer part and a shorter part
extending along and parallel to the longer part such that each end
of the longer part extends past each end of the shorter part; and
the printhead dies in each of the first and second modules extend
lengthwise along the longer part of the module.
8. The print bar of claim 7, wherein each printhead die includes
multiple electrical contacts thereon extending along a side of the
printhead die opposite the shorter part of the module.
9. A modular print bar assembly, comprising: multiple modules each
having a longer edge along a longer part of the module and a
shorter edge along a shorter part module, the longer part of each
module extending along and parallel to the shorter part of each
module such that each end of the longer part extends past each end
of the shorter part; multiple printhead dies on the longer part of
each module; an array of orifices across each printhead die through
which liquid may be dispensed from the printhead die; multiple
electrical contacts on each printhead die extending across the
printhead die between the orifice array and the longer edge of the
module; multiple conduits across each module for carrying liquid to
the printhead dies; and an inlet to each conduit through which
liquid may introduced into the conduit.
10. The assembly of claim 9, wherein: the shorter edges of the
modules are substantially aligned with one another; and the longer
edges of the modules are substantially aligned with one
another.
11. The assembly of claim 10, wherein the printhead dies are
arranged on each module such that the orifice array on each
printhead die extends parallel to a long axis of the module.
12. The assembly of claim 11, wherein the orifice array in a first
printhead die on each module is offset from the orifice array in a
last printhead die on an adjoining module in a media transport
direction but otherwise forms a substantially seamless continuation
of the orifice array in a transverse direction.
13. The assembly of claim 11, wherein an orifice array in a first
printhead die on each module is offset from an orifice array in a
last printhead die on an adjoining module in a media transport
direction and overlaps the orifice array in the last printhead die
in the adjoining module in a transverse direction.
14. The assembly of claim 11, further comprising multiple groups of
electrical conductors, each group of conductors routed over the
longer edge of a corresponding one of the modules and the
conductors in each group connected to the electrical contacts on
the printhead dies on the corresponding module.
15. The assembly of claim 14, further comprising multiple regulator
units each located along a corresponding module and operatively
connected to one or more of the inlets for controlling the flow and
regulating the pressure of liquid supplied to the module, each
regulator unit having a supply port overhanging the shorter edge of
the corresponding module.
Description
BACKGROUND
[0001] In some inkjet printers a media wide array of stationary
printheads is used to print on media moving past the array. For
wider media, greater than 12'' for example, individual printhead
modules each holding several printhead dies are usually arranged in
a staggered configuration in which adjacent modules are offset from
one another in the direction the media moves past the printheads.
Also, the individual printhead dies within each module usually are
also arranged in a staggered, offset configuration, thus creating a
compound stagger--die to die and module to module. Offset array
configurations make overall printer space less efficient and they
present significant difficulties coordinating ink drop placement
between printhead dies and between printhead modules to minimize
print defects inherent in the staggered configuration.
DRAWINGS
[0002] FIG. 1 is a block diagram illustrating one embodiment of an
inkjet printer.
[0003] FIG. 2 is a bottom plan view illustrating a media wide
modular print bar, such as might be used in the printer of FIG. 1,
according to one embodiment of the disclosure.
[0004] FIGS. 3 and 4 are more detailed bottom plan views of
adjoining printhead modules from the print bar of FIG. 2.
[0005] FIGS. 5 and 6 are more detailed views of one example
embodiment of a joint between individual printhead dies in the
module shown in FIG. 3.
[0006] FIGS. 7 and 8 are more detailed views of one example
embodiment of the joints between individual printhead modules in
the print bar of FIG. 2.
[0007] FIGS. 9 and 10 illustrate another example embodiment of the
joints between individual printhead modules in a modular print
bar.
[0008] FIGS. 11 and 12 illustrate another example embodiment of the
joints between individual printhead modules in a modular print
bar.
[0009] FIGS. 13 and 14 are top plan views of adjoining printhead
modules illustrating one example embodiment for supplying ink to
each module.
[0010] FIG. 15 is a detailed view of a portion of the printhead
module shown in FIG. 13.
[0011] FIG. 16 is a side elevation view illustrating one example
embodiment of a pressure regulator unit for supplying ink to a
printhead module.
DESCRIPTION
[0012] Embodiments of the new print bar were developed in an effort
to shrink the print zone in the media transport direction with a
readily scalable printhead array that allows high quality printing
across media widths of up to several meters. Embodiments are
described with reference to inkjet printing. The embodiments shown
in the figures and described below, however, are non-limiting
examples. Other embodiments are possible and nothing in the
following description should be construed to limit the scope of the
disclosure, which is defined in the Claims that follow this
Description.
[0013] Although embodiments of the new print bar are not
necessarily limited to dispensing ink or other liquids, and may be
used for dispensing other fluids, inkjet printheads generally are
not practical for dispensing fluids composed primarily of gas(es).
Thus, "liquid" as used in this document means a fluid not composed
primarily of a gas or gases. A "printhead" as used in this document
refers to that part of an inkjet type drop dispensing structure or
assembly that expels drops of liquid from one or more openings,
typically an array of hundreds or thousands of tiny orifices. A
"printhead" is not limited to printing with ink but also includes
inkjet type dispensing of other liquids and/or for uses other than
printing. "Media transport direction" means a direction parallel to
the axis along which the print media would move past the printhead
modules in a print bar if the print bar were installed in a
printer. "Transverse direction" means a direction across the media
transport direction. A transverse direction is not necessarily
perpendicular to the media transport direction.
[0014] FIG. 1 is a block diagram illustrating an inkjet printer 10
that includes a print bar 12 spanning the width of a print media
14. Printer 10 also includes regulator units 16 associated with
print bar 12, a media transport mechanism 18, an ink supply 20, and
an electronic printer controller 22. Print bar 12 in FIG. 1
represents generally an array of modules each carrying one or more
printhead dies and the associated mechanical and electrical
components for ejecting drops of ink on to a sheet or continuous
web of paper or other print media 14. A typical thermal inkjet
printhead die, for example, includes an orifice plate arrayed with
ink ejection orifices and firing resistors formed on an integrated
circuit chip positioned behind the ink ejection orifices. The
printhead die(s) in each module are electrically connected to
printer controller 22, typically through a flexible circuit tape
holding multiple electrical conductors (often called signal
traces), and fluidically connected to ink supply 20 through
regulator units 16. In operation, printer controller 22 selectively
energizes ink ejector elements in a printhead die, or group of
printhead dies, in the appropriate sequence to eject ink on to
media 14 in a pattern corresponding to the desired printed image.
Controller 22 in FIG. 1 represents generally the programming,
processor(s) and associated memories, and the electronic circuitry
and components needed to control the operative elements of a
printer 10.
[0015] FIG. 2 is a bottom plan view illustrating one embodiment of
a media wide modular print bar 24, such as might be used for print
bar 12 in the printer of FIG. 1. FIGS. 3 and 4 are more detailed
plan views of adjoining printhead modules 26 and 28 in print bar
24. Print bar 24 and modules 26, 28 in FIGS. 2-4 are viewed looking
into the exposed ink ejection orifices, typically the bottom of the
print bar 24 when the print bar 24 is installed in a printer.
[0016] Referring to FIGS. 2-4, print bar 24 includes multiple
individual printhead modules 26 and 28 joined end to end with one
another. Each printhead module 26, 28 includes multiple individual
printhead dies 30 and 32 joined end to end with one another on a
substrate 33. Printhead dies 30 and 32 are located on a longer part
34 of substrate 33 along the bottom 35 of each module 26, 28.
Electrical contacts 36 are located along the outboard side 38
(FIGS. 5 and 6) of each die 30, 32 for connection to external
circuits. Thus, power and other electrical conductors are routed to
printhead dies 30, 32 over a longer edge 39 of substrate longer
part 34 at the bottom 35 of each module 26, 28, resulting in an
alternating configuration of the flex circuits or other suitable
cabling feature 40 (FIG. 2) carrying power and other signal traces
to modules 26 and 28. As described in more detail below with
reference to FIGS. 13-16, ink is routed to printhead dies 30, 32
through flow control, pressure regulator units or other suitable
ink supply features 42 (FIG. 2) over a shorter edge 43 of a
substrate shorter part 44 along the top 45 (FIGS. 13-16) of each
module 26, 28, resulting in an alternating configuration of ink
supply units 42. This alternating configuration allows cabling 40
to be routed straight into each module 26, 28 to help minimize the
length and thus the electrical resistance of the signal traces.
Where, as here, cabling 40 is routed over longer edges 39, then the
ink supply should be routed over shorter edges 43 in a similar
alternating configuration if the ink is to be brought in from the
sides of modules 26, 28.
[0017] FIGS. 5 and 6 are detailed views of one example embodiment
of the joints between individual printhead dies 30 in each module
26 and 28 shown in FIG. 2-4. Due to the smaller scale of FIGS. 2-5,
the array of ejector orifices is indicated generally by a
centerline 46. The details of one example embodiment for an orifice
array 46 are shown in the larger scale of FIG. 6 in which array 46
consists of four pairs 48 of rows 50 of orifices 52--the orifices
52 in each pair of rows 50 may be used to eject a different color
ink, cyan, magenta, yellow and black (CMYK) for example. Referring
to FIGS. 5 and 6, orifice array 46 is offset in a triangular
configuration 53 at one end 54 of each printhead die 30, 32 and
both ends 54 and 56 of each die 30, 32 are sloped along triangular
offset 53 such that orifice array 46 (and orifices 52) overlap at
the joint 58 between dies 30 and 32. Although a triangular offset
configuration is shown, other suitable overlapping arrangements may
be used. While this overlap arrangement makes it easier to minimize
print defects at the joint between dies, this arrangement is not
easily scaled up for use in media wide printing for wider print
media. A single printhead die is currently limited to about 1'' in
width due to structural and processing limitations of the silicon
die material. In addition, the number of dies that can be mounted
together in a single printhead module is limited by the capacity of
the mounting substrate to hold the dies in a flat plane. As the
width of the printhead module exceeds about 8'' (with 1''
individual printhead dies, for example), a "potato chip" effect is
observed in which the printhead dies are no longer held uniformly
in a flat plane. Thus, a new modular print bar has been developed
to shrink the print zone in the media transport direction with a
readily scalable printhead array for printing across wider print
media.
[0018] FIGS. 7 and 8 are more detailed views of one example
embodiment of the joints between individual printhead modules 26
and 28 in print bar 24 (FIG. 2). Referring to FIGS. 7 and 8, the
step 60 formed by the offset between longer and shorter parts 34
and 44 at the ends 62, 64 of each module 26, 28 fit together to
form overlapping joints 66 (FIG. 7) and 68 (FIG. 8). This type of
joint is commonly referred to as a lap joint. Thus, modules 26 and
28 are lapped together end to end at joints 66 and 68. (Where, as
here, the parts joined are in line with one another, the lap joint
is sometimes referred to as a half lap or half lap splice.)
[0019] Referring now to FIG. 7, printhead dies 30 in modules 26 are
oriented such that an offset die end 54 is adjacent to module right
end 64 at joint 66. Printhead dies 32 in modules 28 are oriented
such that a non-offset die end 56 matching offset die end 54 in
module 26 is adjacent to module left end 62 at joint 66.
Conversely, and referring to FIG. 8, printhead dies 32 in modules
26 are oriented such that a non-offset die end 56 is adjacent to
module left end 62 at joint 68 and printhead dies 30 in modules 28
are oriented such that an offset die end 54 is adjacent to module
right end 64 64 at joint 68. In an alternative configuration shown
in FIGS. 9 and 10, modules 26 and 28 are lapped together at joints
66 and 68 through a sloped transition 67 between longer part 34 and
shorter part 44. Thus, the orifice arrays 46 (and, therefore,
orifices 52) in printhead modules 26 and 28 overlap at each lap
joint 66 and 68. In these configurations, orifice arrays 46 in
modules 26 and 28 are minimally offset from one another in the
media transport direction but otherwise form a substantially
seamless orifice array 46 in the transverse direction from module
to module to module, etc.
[0020] The use of a lap joint allows overlapping orifice arrays 46
at joints 66 and 68 without staggering printhead modules 26 and 28,
thus combining the benefits associated with overlapping orifices
(ease in minimizing print defects along the joints) with the
benefits of a linear array of printhead modules (space efficient
and scalable). To accommodate lap joints 66 and 68, the line of
printhead dies 30, 32 in adjoining modules 26 and 28 is offset in
the media transport direction. That is to say, the line of
printhead dies in adjoining modules is staggered in the media
transport direction. This offset/stagger, however, is on the order
of the width of a printhead die which is much smaller than the
stagger/offset in conventional media wide array of printhead
modules.
[0021] FIGS. 11 and 12 illustrate another example embodiment of
joints 66 and 68. Referring to FIG. 11, printhead dies 30 are
oriented such that an offset die end 54 is adjacent to the right
end 64 in modules 26 and to the left end 62 of modules 28 at joint
66. Referring to FIG. 12, printhead dies 30 are oriented such that
a non-offset die end 56 is adjacent to the left end 62 of modules
26 and to the right end 64 of modules 28 at joint 68. The
configuration of dies 30 at joints 66 and 68 in FIGS. 11 and 12 may
be advantageous in some implementations because it allows for
identical printhead dies 30 on each printhead module 26 and 28.
That is to say, the end printhead dies are the same as the other
printhead dies on each module 26, 28 in the die configuration shown
in FIGS. 11 and 12. In the die configuration of FIGS. 7-10, by
contrast, each end die 32 is different from the other dies 30.
[0022] FIGS. 13 and 14 are plan views of adjoining printhead
modules 26 (FIG. 13) and 28 (FIG. 14) illustrating one example
embodiment for supplying ink to modules 26 and 28 and distributing
ink to each printhead die 30, 32. FIG. 15 is a detailed view of a
portion of printhead module 26 shown in FIG. 13. FIG. 16 is a side
elevation view illustrating one example embodiment of a regulator
unit 70, such as might be used for regulator units 16 in FIG. 1.
Referring to FIGS. 13-16, in the example embodiment shown, four
regulator units 70 are operatively coupled to each printhead module
26, 28. Each regulator unit 70 may be used to supply a different
color ink, cyan, magenta, yellow and black (CMYK) for example.
Referring specifically to FIG. 16, ink is pumped or otherwise
delivered to each regulator unit 70 at an inlet 72, from a remote
ink supply 20 (FIG. 1) for example. Each regulator unit 70
represents generally any suitable combination of elements for
controlling the flow and regulating the pressure of ink supplied to
printhead modules 26 and 28. In a typical regulator unit 70, for
example, ink flows from inlet 72 through a flow control valve 74,
pressure regulator 76, and filter 78 to an outlet 80, and from
outlet 80 to an inlet 82 to printhead module 26. The components of
regulator unit 70 may include conventional flow control, pressure
regulator and filter components well known to those skilled in the
art of inkjet printing. Although a separate pressure regulator unit
70 is shown for each of four different color inks, other
configurations are possible. For example, a single, dual-chambered
regulator unit 70 may be used to supply two different color inks to
two module inlets 82.
[0023] Referring again to FIGS. 13-16, ink is distributed from
module inlets 82 to printhead dies 30, 32 in each module 26, 28
through a series of conduits 84 that span the length of dies 30,
32. Using the example noted above, each conduit 84 carries a
different color ink from the corresponding pressure regulator unit
70 to printhead dies 30 and 32. Other configurations are possible.
For example, more than four conduits will be used if additional
inks or other fluids are desired. Openings (not shown) along the
bottom of each conduit 84 allow ink to flow into the slots in each
printhead die 30, 32 that feed the expulsion chambers (not shown)
for individual orifices 52 (FIG. 6). For the orifice array 46 shown
in FIG. 6, each conduit 84 would supply a different color ink to
each pair 48 of rows 50 of orifices 52 (through the corresponding
feed slots and firing chambers in printhead dies 30, 32). In the
embodiment shown in FIGS. 13-16, ink is routed to each inlet 72
over the shorter edge 43 of module shorter part 44. This
configuration facilitates the adaptation of a conventional pressure
regulator unit for use as unit 70 and helps provide clearance for
ink supply lines (not shown) into inlets 72.
[0024] The present disclosure has been shown and described with
reference to the foregoing exemplary embodiments. It is to be
understood, however, that other forms, details and embodiments may
be made without departing from the spirit and scope of the
disclosure which is defined in the following claims.
* * * * *